Emotion: Biology, Theories, and Cultural Influence

1 – Defining Emotion

1.1 – Introduction

Expression of emotion: Toddlers can cycle through emotions quickly, being (a) extremely happy one moment and (b) extremely sad the next.

As we move through our daily lives, we experience a variety of emotions (which we often call “feelings”). Emotions are subjective states of being that, physiologically speaking, involve physiological arousal, psychological appraisal and cognitive processes, subjective experiences, and expressive behavior. Emotions are often the driving force behind motivation (whether positive or negative) and are expressed and communicated through a wide range of behaviors, such as tone of voice and body language.

Our psychological appraisal of a situation is informed by our experiences, background, and culture. Therefore, different people may have different emotional experiences of similar situations. However, the ability to produce and recognize emotional facial expressions seems to be universal. That said, cultures differ in how often and under what circumstances it is “okay” to express various emotions, as well as how various expressions of emotions are interpreted.

1.2 – Emotions and Psychology

How emotions are experienced, processed, expressed, and managed is a topic of great interest in the field of psychology. Psychological research investigates the mental, physiological, and behavioral components of emotion as well as the underlying physiological and neurological processes.

The field of clinical psychology involves diagnosing and treating emotional disturbances and mental disorders that interfere with a person’s well-being and quality of life. In many instances, such treatment may involve emotion regulation, in which people use cognitive and behavioral strategies to influence their own emotional experience. Different theoretical approaches to psychotherapy may involve different strategies for emotion regulation.

1.3 – Emotions vs. Mood

The words emotion and mood are sometimes used interchangeably, but in the field of psychology they refer to two different things. Typically, the word emotion indicates a (generally conscious) subjective, affective state that is often intense and that occurs in response to a specific experience. Mood, on the other hand, refers to a prolonged, less intense affective state that does not necessarily occur in response to something we experience. Unlike emotions, mood states may not be consciously recognized (Beedie, Terry, Lane, & Devonport, 2011).

2 – Biology of Emotion

Emotions can be explained in biological and neurological terms. The limbic system, autonomic nervous system, and reticular activating system all interact to assist the body in experiencing and processing emotions.

2.1 – The Limbic System

The limbic system is the area of the brain most heavily implicated in emotion and memory. Its structures include the hypothalamus, thalamus, amygdala, and hippocampus. The hypothalamus plays a role in the activation of the sympathetic nervous system, which is a part of any emotional reaction. The thalamus serves as a sensory relay center; its neurons project signals to both the amygdala and the higher cortical regions for further processing. The amygdala plays a role in processing emotional information and sending that information on to cortical structures. The hippocampus integrates emotional experience with cognition.

The limbic system: The limbic system is the area of the brain involved with emotion and memory. Its structures include the hypothalamus, thalamus, amygdala, and hippocampus

The processes of the limbic system control our physical and emotional responses to environmental stimuli. This system categorizes the experience of an emotion as a pleasant or unpleasant mental state. Based on this categorization, neurochemicals such as dopamine, noradrenaline, and serotonin increase or decrease, causing the brain’s activity level to fluctuate and resulting in changes in body movement, gestures, and poses.

2.2 – The Amygdala

The amygdala, located in the left and right temporal lobes of the brain, has received a great deal of attention from researchers investigating the biological basis of emotions, particularly of fear and anxiety (Blackford & Pine, 2012; Goosens & Maren, 2002; Maren, Phan, & Liberzon, 2013). The amygdala plays a decisive role in the emotional evaluation and recognition of situations as well as in the analysis of potential threats. It handles external stimuli and induces vegetative reactions.

Two parts of the amygdala include the basolateral complex and the central nucleus. The basolateral complex has dense connections with a variety of sensory areas of the brain. It plays a critical role in classical conditioning and in attaching emotional value to learning processes and memories. The central nucleus plays a role in attention. It has connections with the hypothalamus and various areas of the brainstem and regulates the activity of the autonomic nervous and endocrine systems (Pessoa, 2010).

Research suggests that the amygdala is involved in mood and anxiety disorders. Changes in amygdala structure and function have been found in adolescents who either are at risk for or have been diagnosed with a mood or anxiety disorder (Miguel-Hidalgo, 2013; Qin et al., 2013). It has also been suggested that functional differences in the amygdala could be used to differentiate individuals suffering from bipolar disorder from those suffering from major depressive disorder (Fournier, Keener, Almeida, Kronhaus, & Phillips, 2013).

2.3 – The Hippocampus

The hippocampus is also involved in emotional processing. As with the amygdala, research has demonstrated that hippocampal structure and function are linked to a variety of mood and anxiety disorders. Individuals suffering from posttraumatic stress disorder ( PTSD ) show marked reductions in volume in several parts of the hippocampus, which may be the result of decreased levels of neurogenesis and dendritic branching (the generation of new neurons and the generation of new dendrites in existing neurons, respectively) (Wang et al., 2010). While it is impossible to determine causation, studies have found improvements in behavior as well as increase in hippocampal volume following either pharmacological or cognitive behavioral therapy in individuals suffering from PTSD (Bremner & Vermetten, 2004; Levy-Gigi, Szabó, Kelemen, & Kéri, 2013).

2.4 – The Autonomic Nervous System

The autonomic nervous system (ANS) is part of the peripheral nervous system in humans. It is regulated by the hypothalamus and controls our internal organs and glands, including such processes as pulse, blood pressure, breathing, and arousal in response to emotional circumstances. The ANS is generally thought to be outside of voluntary control.

The ANS can be further subdivided into the sympathetic and parasympathetic nervous systems. When activated, the sympathetic nervous system (SNS) controls the endocrine glands to prepare the body for emergency action. SNS activation causes the adrenal glands to produce epinephrine (also known as adrenaline), which results in the “fight-or-flight” response. The fight-or-flight response involves increased blood flow to the muscles, increased heart rate, and other physiological responses that enable the body to move more quickly and feel less pain in situations perceived to be dangerous.

Conversely, the parasympathetic nervous system (PN) functions when the body is relaxed or at rest; it helps the body store energy for future use. Effects of PN activation include increased stomach activity and decreased blood flow to the muscles.

The parasympathetic and sympathetic divisions of the ANS have complementary functions, and they operate in tandem to maintain the body’s equilibrium. Equilibrium of the body, in which biological conditions (such as body temperature) are maintained at optimal levels, is known as homeostasis.

2.5 – The Reticular Activating System

The reticular activating system (RAS) is a network of neurons that runs through the core of the hindbrain and into the midbrain and forebrain. The RAS is made up of the midbrain reticular formation, the mesencephalic nucleus (mesencephalon), the thalamic intralaminar nucleus (centromedian nucleus), the dorsal hypothalamus, and the tegmentum.

The reticular activating system: The reticular activating system is involved in arousal and attention, sleep and wakefulness, and the control of reflexes.

The RAS is involved with arousal and attention, sleep and wakefulness, and the control of reflexes. The RAS is believed to first arouse the cortex and then maintain its wakefulness so that sensory information and emotion can be interpreted more effectively. It helps us fulfill goals by directing our concentration toward them and plays a role in individuals’ responses to situations and events.

3 – Theories of Emotion

3.1 – Appraisal Theory of Emotion

3.1.1 – Introduction

Researchers have developed several theories of how human emotions arise and are represented in the brain. The mechanisms behind our experience of emotions and our cognitive processing of them remains a central topic of research and debate. The appraisal theory of emotion, developed primarily through the work of prominent researchers Magda Arnold and Richard Lazarus, proposes that emotions are extracted from our “appraisals” (i.e., our evaluations, interpretations, and explanations) of events. The central question that the appraisal theory seeks to answer is why different people have different perceptions of and emotional reactions to the same situations.

For example, if a person goes on a romantic date and perceives this date as positive, they might feel happiness, joy, giddiness, excitement, or anticipation because they have appraised this event as one that could have positive effects. On the other hand, if the date is perceived negatively, the person’s resulting emotions might include dejection, sadness, emptiness, or fear (Scherer et al., 2001).

3.1.2 – Magda B. Arnold

Magda Arnold (1903–2002) was an American psychologist who coined the term appraisal to refer to the cognitive processes preceding the elicitation of emotion. She developed her “cognitive theory” in the 1960s, which specified that the first step in experiencing an emotion is an appraisal of the situation. According to Arnold, an initial appraisal begins the emotional sequence by arousing both the appropriate physiological reactions and the emotional experience itself. In this way, she identified physiological changes as important to the process but not as the initiator of people’s reactions and experiences.

3.1.3 – Richard Lazarus

Psychologist Richard Lazarus (1991) adapted Arnold’s work slightly in the development of his cognitive-mediational theory, which asserts our emotions are determined by our appraisals of stimuli. This appraisal mediates between the stimulus and the emotional response, and it is immediate and often unconscious. In contrast to the Schachter–Singer theory of emotions, which views emotion as an outcome of the interaction between physiological arousal and cognition, Lazarus argued that the appraisal precedes cognitive labeling, simultaneously stimulating both the physiological arousal and the emotional experience itself.

Comparing the theories of emotion: This figure illustrates how Lazarus’ appraisal theory differentiates from the James–Lange, Cannon–Bard, and Schachter–Singer theories of emotion. (click image to enlarge)

Lazarus argued that the cognitive activity involved in interpreting emotional context could be conscious or unconscious and may or may not take the form of conceptual processing. He stressed that the quality and intensity of emotions are controlled through cognitive processes, which mediate the relationship between the person and the environment through coping strategies, which in turn are the basis of the emotional reaction.

Lazarus: Primary and secondary appraisal: According to Lazarus’ cognitive-mediational theory, upon encountering a stressor, a person judges its potential threat (via primary appraisal) and then determines if effective options are available to manage the situation (via secondary appraisal). Stress is likely to result if a stressor is perceived as threatening and few or no effective coping options are available. (click image to enlarge)

In his research, Lazarus specified two major types of appraisal methods: 1) primary appraisal, which seeks to establish the significance or meaning of an event, and 2) secondary appraisal, which assesses the ability of the individual to cope with the consequences of the event. In the specific context of emotion and stress, Lazarus described primary appraisals as judgments about the degree of potential harm or threat to well-being that a stressor might introduce. The perception of a threat then triggers the secondary appraisal—judgment of the options available to cope with the stressor—as well as perceptions of how effective such options will be.

3.2 – James-Lange Theory of Emotion

Researchers have developed several theories of how human emotions arise and are represented in the brain. The James–Lange theory of emotion, for instance, asserts that emotions arise from physiological arousal: in essence, that the self-perception of changes in the body produce emotional experiences. According to this theory, we laugh (a physiological response to a stimulus), and consequently we feel happy (an emotion); we cry, and consequently we feel sad.

For example, if you were to encounter a venomous snake in your backyard, your sympathetic nervous system (responsible for activating your fight-or-flight response) would initiate physiological arousal, making your heart race and increasing your breathing rate. According to the James–Lange theory of emotion, you would experience a feeling of fear only after this physiological arousal had taken place. Different arousal patterns would be associated with different feelings.

James–Lange theory: The James–Lange theory of emotion states that emotions arise as a result of physiological arousal.

One limitation of this theory is that it is not known exactly what causes the changes in the body, so it is unclear whether those changes should be considered part of the emotion itself. Critics of the James–Lange theory also doubt that there is sufficient variation in physiological arousal to lead to the wide variety of emotions that we experience. To address these limitations, other theories—such as the Cannon–Bard theory—have been developed.

3.3 – Cannon-Bard Theory of Emotion

Researchers have developed several theories of how human emotions arise and are represented in the brain. The Cannon–Bard theory of emotion was developed by researchers who criticized the James–Lange theory for its limited ability to account for the wide variety of emotions experienced by human beings. While the James–Lange theory proposes that emotions arise from physical arousal the Cannon–Bard theory argues that physiological arousal and emotional experience occur simultaneously, yet independently (Lang, 1994).

This theory posits that when you see a venomous snake in your backyard, you feel fear at exactly the same time that your body initiates its physiological fight-or-flight response. Even though they occur at the same time, your emotional reaction and your physiological reaction would be separate and independent.

According to the Cannon–Bard theory, emotional expression results from activation of the subcortical centers of the brain. The optic thalamus, in particular, is a region that contains the neural organizations for different emotional expressions. An individual’s sensory organs take in an emotional stimulus, and then information about that stimulus is relayed to the cerebral cortex. It is in the cortex where such information is associated with conditioned processes, which in turn determine the direction of the response and stimulate the thalamic processes.

3.4 – Schachter-Singer Theory of Emotion (Two-Factor Theory)

Researchers have developed several theories of how human emotions arise and are represented in the brain. Like the James–Lange and Cannon–Bard theories, the Schachter–Singer theory of emotion (also known as the two-factor theory) attempts to explain emotion as it relates to physiological arousal.

According to the Schacter–Singer theory, emotion results from the interaction between two factors: physiological arousal and cognition. More specifically, this theory claims that physiological arousal is cognitively interpreted within the context of each situation, which ultimately produces the emotional experience. These cognitive interpretations —how a person labels and understands what they are experiencing—are formed based on the person’s past experiences.

The Schachter–Singer two-factor theory: The Schachter–Singer theory views emotion as resulting from the interaction of two factors: physiological arousal and cognition.

For example, if you were to see a venomous snake in your backyard, the Schachter–Singer theory argues that the snake would elicit sympathetic nervous system activation (physiological arousal) that would be cognitively labeled as fear (cognition) based on the context. What you would actually experience, then, would be the feeling of fear.

In their research, Singer and Schachter injected participants with adrenaline (epinephrine), which causes a number of physiological effects, such as increased blood flow to the muscles and increased heart rate. They found that injecting the drug did not lead participants to experience any given emotion. Contrary to the James–Lange theory, therefore, which asserts that emotions arise from physiological arousal, this theory argues that bodily changes can support conscious emotional experiences but do not necessarily cause them. Rather, the interpretation of a certain emotion depends on both the individual’s physiological state as well as their circumstances, a relationship mediated by cognitive processing.

3.5 – The Facial Feedback Hypothesis

3.5.1 – Introduction

The impact of facial expressions: According to the facial feedback hypothesis, facial expressions aren’t simply caused by emotions—they can influence our emotions as well. Smiling more frequently over a period of time can, in fact, make you feel happier.

Does smiling make you happy, or does being happy make you smile? The facial feedback hypothesis asserts facial expressions are not only the results of our emotions but are also capable of influencing our emotions. In other words, the act of smiling can itself actually make you feel happier. (Buck, 1980; Soussignan, 2001; Strack, Martin, & Stepper, 1988).

3.5.2 – Research into the Facial Feedback Hypothesis

Research investigating the facial feedback hypothesis has found that suppressing facial expressions of emotion may decrease how intensely those emotions are experienced (Davis, Senghas, & Ochsner, 2009).

Recently, the use of Botox to temporarily paralyze facial muscles has also provided strong experimental support for some kind of facial-feedback mechanism involved in emotion. Havas, Glenberg, Gutowski, Lucarelli, and Davidson (2010) discovered that individuals with depression reported lessened depressive symptoms after paralysis of their frowning muscles with Botox injections. Findings from this and other studies suggest that facial feedback modulates the neural processing of emotional content.

In an attempt to objectively assess the facial feedback hypothesis, Strack, Martin, and Stepper (1988) devised an experiment that would hide their true goals from the participants. Participants were simply told that they were taking part in a study to determine the difficulty of accomplishing certain tasks for people who do not have the use of their hands or arms. To this end, participants held a pen in their mouth in one of three ways: the Lip position would contract the orbicularis oris muscle, resulting in a frown; the Teeth position would contract the zygomaticus major or the risorius muscle, resulting in a smile; and the control group would hold the pen in their non-dominant hand. All participants had to complete a questionnaire while holding the pen and rate the difficulty of doing so. The last task, which was the experiment’s real object of interest, was for the participants to subjectively rate the the funniness of a cartoon. As predicted, participants in the Teeth condition (who were, technically, smiling throughout the exercise) reported significantly higher amusement ratings than those in the Lips condition. This outcome supported the facial feedback hypothesis.

Of course, emotion is displayed not only through facial expression but also through tone of voice and behavior. Specifically, body language is the expression of emotion through body position and movement. Research suggests that we are quite sensitive to the emotional information communicated through body language, even if we’re not consciously aware of it (de Gelder, 2006; Tamietto et al., 2009).

3.5.3 – Autism and Emotional Expression

Autism spectrum disorder (ASD) is a set of neurodevelopmental disorders characterized by repetitive behaviors and difficulties with communication and social interaction. Children who have ASD have difficulty recognizing the emotional states of others; research has shown that this may stem from an inability to differentiate among various nonverbal expressions of emotion (e.g., facial expressions) (Hobson, 1986). There is also evidence that suggests that individuals with ASD have difficulty expressing their own emotion through tone of voice and facial expressions (Macdonald et al., 1989).

Difficulties with emotional recognition and expression may contribute to the impaired social interaction and communication that characterize ASD. Various therapeutic approaches have been explored to address these difficulties: different educational curricula, cognitive behavioral therapies, and pharmacological therapies have shown some promise in helping individuals with ASD to process emotionally relevant information (Bauminger, 2002; Golan & Baron-Cohen, 2006; Guastella et al., 2010).

4 – Influence of Culture on Emotion

4.1 – Introduction

Culture—i.e., the beliefs, values, behavior, and material objects that constitute a people’s way of life—can have a profound impact on how people display, perceive, and experience emotions. The culture in which we live provides structure, guidelines, expectations, and rules to help us understand and interpret various emotions.

4.2 – Expression Emotions

A cultural display rule dictates the types and frequencies of emotional displays considered acceptable within a certain culture (Malatesta & Haviland, 1982). These rules may also guide how people choose to regulate their emotions, ultimately influencing an individual’s emotional experience and leading to general cultural differences in the experience and display of emotion.

For example, in many Asian cultures, social harmony is prioritized over individual gain, whereas Westerners in much of Europe and the United States prioritize individual self-promotion. Research has shown that individuals from the United States are more likely to express negative emotions such as fear, anger, and disgust both alone and in the presence of others, while Japanese individuals are more likely to do so only while alone (Matsumoto, 1990). Furthermore, individuals from cultures that tend to emphasize social cohesion are more likely suppress their own emotional reaction in order to first evaluate what response is most appropriate given the situation (Matsumoto, Yoo, & Nakagawa, 2008).

Cultures also differ in the social consequences that they assign to different emotions: in the United States, men are often directly or indirectly ostracized for crying; in the Utku Eskimo population, the expression of anger can result in social ostracism.

Within a particular culture, different rules may also be internalized as a function of an individual’s gender, class, family background, or other factor. For instance, there is some evidence that men and women may differ in the regulation of their emotions, perhaps due to culturally based gender norms and expectations (McRae, Ochsner, Mauss, Gabrieli, & Gross, 2008).

4.3 – Interpreting Emotions

In everyday life, information from the environment influences our understanding of what facial expressions mean. In much the same way, cultural context also acts as a cue when people are trying to interpret facial expressions. People can attend to only a small number of the available cues in their complex and continuously changing environments, and increasing evidence suggests that people from different cultural backgrounds allocate their attention very differently. This means that people from different cultures may interpret the same social context in very different ways.

4.4 – Are Emotions Universal?

Although conventions regarding the display of emotion differ from culture to culture, our ability to recognize and produce associated facial expressions appears to be universal. Research comparing facial expressions across different cultures has supported the theory that there are seven universal emotions, each associated with a distinct facial expression. That these emotions are “universal” means that they operate independently of culture and language. These seven emotions are happiness, surprise, sadness, fright, disgust, contempt, and anger (Ekman & Keltner, 1997). Even congenitally blind individuals (people who are born blind) produce the same facial expressions associated with these emotions, despite never having had the opportunity to observe them in other people. This further supports the theory that the patterns in facial muscle activity are universal for the facial expressions of these particular emotions.

It is worth noting that more complex emotions such as jealousy, love, and pride are different from these more basic emotions, as they involve awareness of the relationships between the self and other people. Complex emotions are therefore more likely to be dependent on cultural differences than are the seven more basic emotions.